Effect of Preheating Conditions of Hydrogen Peroxide on Flow-Type Hydrothermal Partial Oxidation of Methane

Abstract

Methanol is an important industrial material for producing medicine, fuel and resin. It is generally synthesized through the reaction of CO and H₂ in steam reforming of methane. This process is, however, energy consuming; development of a direct method of methanol synthesis that is less energy consuming is required. This paper introduces an experimental study on flow-type hydrothermal oxidation of methane by H₂O₂. Experiments were conducted under different H₂O₂ preheating conditions (no-preheating, 120°C, over 270°C) at reaction temperatures from 100 to 350°C. Methane conversion was significantly higher without preheating than when H₂O₂ was preheated to over 270°C. As a result, methanol yield also increased and showed higher values than previously reported. The increased methane conversion in the absence of preheating was considered to result from elimination of the thermal decomposition of H₂O₂ that would occur during preheating and the formation of strongly oxidizing OH radicals at the reaction site due to the rapid rise in temperature. This experimental results also suggested that all H₂O₂ was decomposed to O₂ before it reached the reaction tube when it was preheated at over 270°C.